1 Field of the Invention
This invention relates to a valve structure of a hydraulic buffer and, more particularly to a valve structure of a hydraulic buffer installed in a suspension of an automobile in which preload is given to a valve body through a compression spring or the like.
2 Description of the Prior Art
As a valve structure for a member like a piston which partitions the interior of a cylinder of a hydraulic buffer into two liquid chambers and has ports affording communication between both liquid chambers, there are ones shown in FIG. 6 and disclosed in Japanese Utility Model Public Disclosure (KOKAI) No. 33842/83, for example.
The interior of a cylinder 10 of a hydraulic buffer shown in FIG. 6 is partitioned into two liquid chambers 16,18 by a piston 14 disposed movably in the cylinder 10 and connected with a piston rod 12. The piston 14 is provided with a plurality of ports 20 through which liquid flows when the piston rod 12 is extended and a plurality of ports 22 through which liquid flows when the piston rod 12 is contracted (only one port is shown respectively in FIG. 6). Both liquid chambers 16,18 communicate to each other through these ports. A valve body 24 formed of a leaf spring is disposed at the underside of the ports 20, while a valve body 26 formed of a leaf spring is disposed at the upside of the ports 22.
This hydraulic buffer is constituted such that while a damping force is produced by the flow of liquid flowing through the ports 20 to deflect the valve body 24 when the piston rod 12 is extended, any damping force is not substantially produced by the flow of liquid flowing through the ports 22 to deflect the valve body 26, when the piston rod 12 is contracted, because of same spring constant of valve body 26.
According to the hydraulic buffer disclosed in said Japanese Utility Model Public disclosure, a valve body for opening and closing ports through which liquid flows when a piston rod is extended, is formed of a leaf spring having a plurlaity of slits at a peripheral portion thereof and biased toward the piston by a compression spring to give preload to the valve body.